Estimation of critical shear stress from cohesive strength meter-derived erosion thresholds

Effect of soil composition on critical water erosion shear stress

A method for measuring the critical shear stress of cohesive soils

Hydraulic erosion of cohesive riverbanks

This study identifies and assesses the controls on hydraulic erosion of cohesive riverbanks on a 600-m reach of an urban ephemeral stream with active bank erosion. We examined hydraulic bank erosion by separating estimated bank shear stress into four properties: magnitude, duration, event peak, and variability. The values of these independent variables were used as a bank erosion context at thr...

Accuracy of MRI wall shear stress estimation

Methods Three methods for WSS estimation were studied. These methods are based on 1) linear extrapolation (LE) of MRI velocity data, 2) MRI velocity data in combination with estimation of location of vessel wall, and 3) Fourier velocity encoding (FVE). Numerical velocity fields representing axisymmetric 2D velocity profiles were generated for WSS values ranging from 1-20 N/m. Based on the numer...

DGPS Directional Signal Strength Meter

Gregory Johnson is a Senior Program Manger at Alion Science & Technology, JJMA Maritime Sector. He heads up the New London, CT office which provides research and engineering support to the Coast Guard Academy and R&D Center. He has a BSEE from the USCG Academy (1987) a MSEE from Northeastern University (1993) and a PhD in Electrical Engineering from the University of Rhode Island (2005). Dr. Jo...